Sterilization (human, elective procedures)

Sterilization procedures are designed to eliminate fertility. Almost all of these are done surgically. In people, these procedures involve disrupting the normal channels that mature gamete cells (ovum and sperm) use for transport to the uterus. In men, that means blocking the vas deferens, so that sperm cannot exit the body. In women, that blockage is placed in the fallopian tube so that ovum cannot reach the uterus. Although there is some success in reversing these procedures, that success is limited and, generally, these surgical means of contraception are permanent.

In animals, surgical sterilization ordinarily involves removal of the gonads such that the animal not only no longer produces gametes (ova or sperm) but that the animal no longer produces the normal sexual hormones of its kind. Although removal both testes in a man, and both ovaries in a woman does certainly cause sterility, these procedures are never done ethically to prevent reproduction, but instead, when performed, are done for treatment of disease. For surgical sterilization in animals, see Desexing operations.

Vasectomy

"Vasectomy is performed on 750,000 men per year in the United States for contraception. Subsequently, approximately 5% of these men have the vasectomy reversed, most commonly because of remarriage."(reference:Paul J. Turek, MD:Chapter 42. Male Infertility in SMITH'S GENERAL UROLOGY - 16th Ed. 2004 ISBN 0071396489) Vasectomy is a simple and inexpensive means of surgical sterilization as compared to any other method. The operative procedure itself is safely performed in a physicians' office or ambulatory surgical suite, and does not require general anesthesia. However, there are long term changes in male physiology, which. although not associated with harm to well being, are significant.

The blocked vas deferens obstructs the passage of sperm, but since there is a store of mature sperm at any given time, the spermatic cord and ejaculatory ducts must be empty before fertility os lost. This process takes about 3 months in most men, and examination of a semen specimen is routinely required before a post-vasectomy patient is considered sterile and relieved of rersponsibilty for his part in birth control.

Risks, complications, adverse effects

Even though the surgery itself is rarely complicated, the change in the body after surgery may have some adverse effects. "Vasectomy frequently triggers both humoral and possibly cell-mediated autoimmune reactions to sperm. After vasectomy, the blood-testis barrier is broken and 60% to 70% of men form antibodies to sperm, which can persist for years.

Fallopian tube procedures

So many women choose tubal sterilisation as a way of birth control, that fallopian tube obstruction has been called "the most popular contraceptive method in the world" (Yossry M. Aboulghar M. D'Angelo A. Gillett W. In vitro fertilisation versus tubal reanastomosis (sterilisation reversal) for subfertility after tubal sterilisation. Cochrane Database of Systematic Reviews. 3:CD004144, 2006. UI: 16856034)

Standard procedures for disrupting the fallopian tubes are surgical procedures. These operations originally were always carried out with convention surgical techniques through an abdominal incision, and, at times, are still done in this manner. Since the introduction of optical teloscopes in surgery and endocopic surgical techniques in the the last part of the 20th century, conventional surgery for fallopian tube procedures has been largely displaced by laproscopic surgery.

Immediately after full-term pregnancy

Surgical access to the fallopian tubes is easier just after a woman gives birth to a full term baby. That's because the enlarged uterus lifts these ducts up towards the anterior abdominal wall and a small incision in the region of the umbilicus (belly button) can give sufficient exposure to perform the surgery. In many parts of the world, consent for elective surgical sterilization must be given separately in both time and place from the performance of that procedure. Women who are pregnant and who would like to have this particular pregnancy be the last one are usually advised by their physician or other health care provider to arrange in advance for surgical disruption of the fallopian tubes after the baby is born. In some regions, this permission must be formalized at least 1 month before the procedure is carried out.

Is fallopian tube obstruction reversible?

The rate of success in reversal in these procedures is dependant on the exact manner in which the tubes were disrupted. Generally, when procedures are dopne that remove lengths of the tube, the procedures give more reliable birth control and are less amenable to reversal. The incidence of reversal has been reported to be between 1to 13% of sterilized women, but in most studies it is only reported as being between 1to 2% If a pregnancy is wanted despite persistent fallopian tube obstruction, then in virto fertilization with implantation of the embryo in the uterus is sometimes successful.